Gaseous electric discharge lamp device



Nov. 12, 1935. w. UYTER'HOEVEN ET AL 72,020,706

GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed Sept. 1, 1934 INVENTORS WM m M 7 BY 6.9

ATTORNEY Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE GASEOUS ELECTRIC DISCHARGE LAMP DEVIC Willem Uyterhoeven and Cornelis Verburg, Bind hoven, Netherlands, assignors to General Elec- -tric Company, a corporation of New York Application September 1,1934, Serial No. 742,396

- In Germany September 25, 1933 '4 Claims.

7 than 1 mm. at a temperature of 200 0., such as sodium, cadmium, magnesium, thallium and zinc, and in which the metal vapor is'a light emitting element, are efficient light sources. The vapor in such devices does not reach an effective op-' erating pressure for an appreciable time after the start of such lamp devices since the device does not reach the temperature 'requiredfor an effective vapor pressure until considerable time has elapsed after the starting period.

The object of the invention is to provide means to shorten the time required for vapor lamps of the above type to reach their operating temperature after the start of the device. Another ob- .ject of the invention is to provide a circuit for such devices whereby the time required for the device to reach its operating temperature and pressure is considerably reduced. A further object of the invention is to provide a simple lamp unit comprising a lamp device of the above type. A further object of the invention is to provide 'an illuminating system comprising a gaseous electric discharge lamp device requiring an appreciable time after starting to attain its operating temperature and another gaseous electric discharge lamp device which attains its operating temperature a short time after starting whereby the time required for said first named device to attain its operating temperature is substantially reduced. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

Inaccordance with these objects the invention' comprises a circuit having a vapor lamp therein of the type requiring an appreciable time after the starting thereof to reach its operating temperature and to build up an effective vapor pressure and another gaseous electric discharge lamp device of the type which reaches its operating temperature a short time after starting. The two lamp devices are connected in series during the operation thereof and means are provided in the circuit to short circuit the lamp device which reaches its operating temperature quickly until the other of said devices has reached its operating temperature. The device requiring an appreciable time to reach its operating temperature is thus considerably overloaded during the starting period thereof and quickly reaches its operating temperature. When 5 said last named device has reached its operating temperature the other of said devices is connected into the circuit in series therewith. Since the discharge device with the short heating time is short circuited during the starting period of the 10 other of said devices, the potential required to start the lamp devices in the circuit into operation is appreciably lower, than is the case when both of said devices are started into operation simultaneously. On an alternating current supl5 ply this lower potential results in an appreciably better performance factor.

In order to avoid the possibility of interrupting the discharge in the device flrst'started when the second device is started into operation a 20 high impedance is connected in the circuit in parallel with the discharge device having a short heating time. This impedance consists of a high resistance, or, in the case of alternating current, the impedance consists of a resistance, choke 25 coil, or a condenser, when desired. A condenser is also useful in connection with the device having the short heating time as the starting thereof is facilitated thereby.

It is desirable toprovide automatic means for connecting into the circuit the device having the short heating time when the device containing the vapor of a metal diflicult to vaporize has reached its operating temperature. If the two devices are mounted in adjacent positions light rays from each lamp are commingled which improves the color of the light emitted by a lamp unit comprising such devices. Discharge devices having a gaseous atmosphere comprising metals which are difiicult to vaporize are usually provided with a heat conservator to reduce the heat losses therefrom. An evacuated envelope enclosing the lamp device or a double walled jacket having the space between the walls thereof evacuated and in which the lamp device is mounted 45 circuit. comprises a gaseous electric discharge lamp device 6 having electrodes which are electron emitting when heated and a gaseous fill ing comprising a fixed, starting gas, such as neon, and the vapor of a difficultly vaporizable material, such as sodium. Said lamp device i is connected across the terminals 2 of an alternating current source and an auto-inductance 3 is connected in series with said lamp device i. A second gaseous electric .discharge lamp device 4 having electrodes which are electron emitting when heated and a gaseous filling consisting of a rare gas, such as neon, is connected in series with said lamp device I. A switch 5 is connected across the terminals of the lamp device t and short-circuits said lamp device l' when closed. The movements of said switch 5 are controlled by a time delay, electro-magnetic relay, the coil 6 of which is connected in series with the lamp devices 11 and l. A resistance 1 is connected in parallel with said lamp device t.

When current is applied to the above described circuit the switch 5 is closed which short circuits the lamp device 5. A strong current is thus applied to the lamp device ll so that said lamp device i is rapidly'heated to its operating temperature and the dimcultly vaporizable material therein is quickly vaporized. The vapor pressure in the lamp device I is rapidly built up to an effective operating pressure at which pressure the vapor emits light when excited by the passage of an electric discharge therethrough.

The relay 8 is so adjusted that as soon as the lamp device i has reached its operating tempera= ture said relay it opens the switch d to connect the lamp device t in series with the lamp device i. The lamp device t is thus started into operation and quickly reaches its operating temperature. The resistance l, connected in parallel with the lamp device 5', prevents the inter ruption of the discharge in said lamp device i when said switch 5 is moved to its open circuit position connecting said lamp device t in series with said lamp .device i.

The electron emitting electrodes in both of said lamp devices it and t are of the indirectly heated type and consist of a heating element, such as a tungsten filament, in operative rela-- tion to a body of electron emitting material, such as barium oxide, when desired, or are of the type heated directly by the discharge and consist of a sintered mixture of metallic and oxide particles, when desired.

The two lamp devices 9 and ii are mounted in adjacent positions to form a lamp unit which emits'light in which the light rays from Tooth of said lamp devices are commingled, when desired, When desired, the lamp .device l is: provided with a heat conservator, such as an evacuated envelope or a double walled jacket having Such ing gas and a limited quantity of mercury which is completely vaporized before said lamp has atin the forms and details of the device illustrated 10 and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent 01 the United States is:-

1. An illuminating system comprising in combination two gaseous electric discharge lamp devices connected in series, one of said devices requiring a longer time to attain the operating temperature thereof than the other of said de- 20,

vices, means to short circuit said last named device until said first named device has attained its operating temperature and a high impedance connected in parallel with said last named device to maintain the discharge in said first named 25. device during the starting period of said last named device.

2. Ari illuminating system comprising in combination two gaseous electric discharge lamp devices connected in series, one of said devices having a gaseous atmosphere therein comprising the vapor of a difiicultly vaporizable material and requiring a longer time to attain the operating temperature thereof than the other of said devices, means to short circuit said last named device until said first named device has attained its operating temperature and a high impedance connected in parallel with said last named device to maintain the discharge in said first nameddevice during the starting period of said last named device.

3. An illuminating system comprising in combination two gaseous electric discharge lamp devices connected in series, one of said devices having a gaseous atmosphere therein comprising sodium vapor and. requiring a longer time to attain the operating temperature thereof than the other of said devices, means to short circuit said last named device until said first named device,

has attained its operating temperature and a high impedance connected in parallel with said last named device to maintain the discharge in said first named device duringthe starting period of said last named device.

4:. An illuminating system comprising in combin-ation two gaseous electric discharge lamp .devices connected in series, one oi said devices requiring a longer time to attain the operating temperature thereof than the other of said devices, means to short circuit said-last named device until said first named device has attained its operating temperature and a high impedance connected in parallel with said last named device to maintain the discharge in said first named device during the starting period of said last named device, said lamps being mounted in adiacent positions, the light rays from both said lamps being commingled.

WILLEM UY'I'ERHOEVEN.

CORNELIS VERBURYG. 7o 

